Surgical procedures, known as ostomies, are some times necessitated due to inflammatory bowel disease, cancer, or injury. An ostomy creates an artificial opening (stoma) in the abdomen for the elimination of bodily waste. Since the ostomy patients are unable to control the passage of bodily waste material, use is made of an appliance attached to the body to collect this material. Conventional available ostomy appliances consist of a pouch, made up of a barrier plastic material, attached to a hydrocolloid containing synthetic rubber based adhesive gasket capable of adhering to the skin around the stoma. The adhesive gasket is capable of anchoring the appliance to the skin for time periods ranging from a few hours to as long as 10 days. The adhesive gasket does protect the peristomal skin. However, it is very difficult for the ostomate to cut a hole in the wafer to fit perfectly around the stoma to achieve a fluid proof seal between the stomal opening of the gasket and the stoma. Even for pre-cut adhesive gaskets it can be difficult to obtain at perfect fit around the stoma, to achieve a fluid proof seal between the stomal opening of the gasket and the stoma. Therefore, some areas of the peristomal skin may remain exposed and become vulnerable to the deleterious effects of the intestinal effluents, which can cause serious irritation, excoriation, and eventual breakdown of the skin contiguous to the stoma. In addition, the fluid leakage may also cause disintegration of the gasket, resulting in breach of its barrier properties and exacerbating the problem of skin protection. Another frequent cause of peristomal skin complications is stomal effluent undermining a skin barrier due to irregularities in stoma placement, stoma shape, retraction or scarring. When peristomal surface unevenness is severe, the appliance gasket may fail to achieve an acceptable seal resulting in undermining of the gasket by the stomal effluent, causing leakage, discomfort and pain. For these reasons, many ostomates use one of the additional means available in the form of pastes, hydrocolloid powders, karaya seal rings, skin barrier rings, or adhesive strips to augment the sealing function of the gasket. One of the disadvantages of such pastes is that some of them contain solvents, which are irritating to skin. Another disadvantage is that the pastes are easily subject to disintegration by absorption of effluent or moisture. Pastes are generally not very cohesive, and therefore often leave residues upon removal. Body movements could also disrupt the sealing properties. Thorough cleaning is required in order that a new plaster may stick well to the application area. This procedure may further irritate the skin.
U.S. Pat. No. 4,204,540 describes a composition adapted for use around the stoma and consisting of a homogeneous mixture of a pressure-sensitive adhesive component, mineral oil, and hydrocolloid gums or cohesive strengthening agents or a mixture of hydrocolloid gums and cohesive strengthening agents. A balance of different components in the mixture provides compositions which can be shaped by hand to seal the skin surface between the gasket and the stoma.
U.S. Pat. No. 4,231,369 describes a gel-like sealant composition composed of a physical mixture of tackified styrene-olefin-styrene block copolymer having at least one hydrocolloid dispersed therein.
U.S. Pat. No. 4,350,785 describes an ostomy paste formulated as mixtures of water absorbing particulate hydrocolloid gums and organic solvent (e.g. alcohol) solutions of adhesive film forming resins, such as poly(methyl vinyl ether/maleic acid), having increased resistance to urine and intestinal fluids by incorporating a small amount of colloidal silica, preferably fumed silica.
U.S. Pat. No. 4,578,065 describes protective sealing compositions in the form of molded rings or sheets, which comprise gelled mixtures of water absorbing particulate hydrocolloid gum and non-toxic polyhydroxyalcohol, having increased resistance to the drained fluid (e.g. urine or intestinal fluids) by incorporating a small amount of fumed silica or colloidal silica gel.
U.S. Pat. No. 4,477,325 to Osburn describes sealant or paste composition of hydrocolloids in a network of an elastomeric copolymer of ethylene and vinyl acetate, and polyisobutylene; the mechanical strength and fluid endurance of which is enhanced by crosslinking, produced by irrradiating the mixture.
U.S. Pat. No. 4,738,257 to Meyer et al describes a continuous elastomeric phase, formed by cross-linking to form a network, and distinguishes itself by stating that in Sorensen and Osburn, above, that after absorbing enough water, the hydrocolloid loses its wet tack, or ability to adhere to the skin to form a sealant or shield.
U.S. Pat. No. 5,496,296 describes an ostomy appliance having an adhesive gasket, which includes a flexible patch which may be formed of non-woven material and is covered on one side with a first layer of moisture absorbing pressure-sensitive adhesive material surrounding the stomal opening, and a second layer of a soft, easily deformable, extrudable fluid resistant gasket that prevents stomal fluids form contacting the peristomal skin surfaces and the first layer of the adhesive and possibly dissolving that layer and/or disrupting its attachment to skin.
WO 2006/075949 describes a pre-formed, very soft sealant ring. It is pre-formed, and so can be limited as to how well it can adapt to a variety of skin sites of different shapes or sizes. The preferred material is described to be silicone rubber, which has adhesion problems to most materials, including SIS and PIB, the common material used for ostomy adhesive plates.
The best fitting sealant achievable would come from a flowable or pliable system which wets out easily into the contours and crevices of the skin and adapts to the surface of the skin. There should also be an increase in cohesion after application for it to function safely and to be easy removable after use.
U.S. Pat. No. 6,068,852 describes a 2 part, polymerizable, skin sealant or shield which cures in-situ at the skin site. It describes the use of acrylic copolymers and monomers which are crosslinked by the use of free radical polymerization initiator.
Acrylic monomers and free radical initiators are known to be toxic to skin. The initiator can also be inhibited by the application environment, such as oxygen, moisture and pH, so that crosslinking can not be achieved effectively. Furthermore, the above mentioned systems use relatively low to very low moisture permeable polymers which are not inducive to transporting moisture away from the skin, giving potential maceration problems.
One solution is to increase the amount of water absorbent material, which has the effect of swelling or weakening the polymer matrix. This in turn reduces the sealing or adhesion properties and the erosion resistance of the seal, leading to reduced wear time and leakage problems.
WO04108175 discloses a 2 component silicone composition for application to the skin.
JP2004067720 discloses a crosslinked polyoxyalkylene based polymer matrix which is pre-reacted at 90° C. on a fabric carrier. Both reaction components for the crosslinked polymer are silicone oligomers or copolymers.
Silicone systems, due to the nature of their surface properties, have adhesion problems with most commonly used adhesives in the medical applications of interest except with silicone based devices. This severely limits the usability of silicone compositions. Furthermore, silicones in general do not have very high water transport properties, thus may lead to maceration problems.
WO 2005/032401 describes a PSA sheet based on PPO polymers having low irritation to the skin and high moisture permeability. It is a pre-formed adhesive crosslinked at over 100° C.
It has now been surprisingly found that liquid PPO polymers can be crosslinked at workable rates at body temperatures on the skin site to provide a very good fit around the contours of the skin site, thereby providing very good sealing or barrier properties against leakage around the stoma. It is soft and comfortable to wear, easy to remove in one piece, skin friendly, and does not cause adhesion problems when later using other types of adhesives.
Furthermore, it provides superior moisture permeability, excellent erosion resistance, again improving safety against leakage, fast curing of between 5 to 30 min. under application conditions.